Device for producing typewritten master printing sheets by means of a transfer pigment carrier



Apnl 1, 1958 H. BELLINGER 2,828,847

DEVICE FOR PRODUCING TYPEWRITTEN MASTER PRINTING SHEETS BY MEANS OF A TRANSFER PIGMENT CARRIER Filed June 29, 1953 ATTORNEY DEVICE FOR PRODUCING TYPEWRITTEN MAS- TER PRIN TING SHEETS BY MEANS OF A TRANS- FER PIGMENT CARRIER Heinrich Bellinger, Frankfurt am Main, Germany Application June 29, 1953, Serial No. 364,780

8 Claims. (Cl. 197-431) It has already become known to produce typewritten reduplicate copies by simple transfer printing from a master printing sheet or paper prepared by means of a conventional typewriter with the aid of a transfer ink or pigment paper. For this purpose, the transfer sheet or paper is placed underneath the printing sheet with its pigment coated surface adjacent to and in contact with the printing sheet. Both superposed sheets are then inserted in a conventional typewriter operated in the ordinary manner. As a result of the type printing pressure, the ink or pigment upon the transfer sheet is removed and transferred to the printing sheet.

in preparing a master printing sheet of this type it is desirable to effect a complete removal or transfer of the ink or pigment coating from the transfer paper to the printing sheet, to enable a maximum number of copies to be made from a single master sheet or matrix. On the other hand, the complete removal of the pigment from the areas of the type impressions constitutes a disadvantage in that it prevents a repeated use of the transfer paper, thus resulting in substantial wastage and greatly reducing the economy of consumption of transfer paper. The reason for this limited utilization or wastage of transfer paper is due to the fact that, in accordance with the previous practice, the transfer sheet is passed at the same speed past the printing point upon the platen roll of the typewriter together with the printing sheet, both sheets being advanced step by step in superposed relation when changing from one to the next printing line in accordance with a selected line spacing. The greater the line spacing the greater the wastage of transfer paper, as is understood.

If a repeated use of transfer paper is desired, great care must be exercised to prevent the new printing impressions from coinciding with any used area of the transfer sheet from which the pigment has been removed previously. In other words, any additional printing impression must coincide with the non-used areas of the transfer sheet or areas between successive printing lines.

This requirement can be fulfilled only with great difiiculty and involves considerable delays in making the necessary adjustments. For this and other reasons, attempts to achieve a better and more economical use of transfer paper have beenfound impractical and unsatisfactory in the past.

An important object of the present invention is therefore to provide an arrangement which will avoid wastage of transfer paper by substantially eliminating unused areas between successive lines of the typing impressions, or by subjecting substantially all the areas of the transfer paper to the same use, irrespective of the line spacing distance between successive printing lines.

A further object of the invention is the provision of a device of this type enabling the provision of an increased supply of transfer paper in the form of a continuous strip wound upon a roll and suitable for preparing a multiple number of printing master sheets.

atent Patented Apr. 1, 1958 A still further object is to provide a device of the above type which can be readily embodied in conventional typewriter structures, either permanently or removably in the form of an auxiliary attachment.

Another object is to provide a device for the special requirements stated, which is simple in construction as well as efficient and reliable in operation.

The invention will be better understood from the following detailed description considered in conjunction with the accompanying drawing forming part of this specification and wherein:

Fig. 1 is a diagrammatic view of a transfer paper feeding mechanism for use in a conventional typewriter structure and embodying the principles of the invention;

Fig. 2 is a similar view showing a modification of the feeding mechanism of Fig. 1; and

Fig. 3 is a diagram illustrating the structural combination of a device according to the invention with the line' advance mechanism of a standard typewriter structure.

Like reference characters identify like parts in the diiferent views of the drawing.

With the foregoing and ancillary objects in view, which will become more apparent as the description proceeds, the invention involves generally the provision of mechanism to afford an independent movement or advance of the printing and transfer papers, respectively, preferably in such a manner that, upon changing from one to the next printing line, the printing sheet is advanced in accordance with the desired line spacing, while the transfer paper is advanced by a fixed distance equal to the height of the largest typing impression and substantially independently of the adjusted line spacing. As a result, no spacing areas will appear between the line impressions upon' the transfer sheet, in that the type impressions of one line will be closely adjacent to the impressions of the adjacent lines. For this purpose, the printing and transfer papers are fed separately past and in contact with the platen roller, to enable a dilferential advance when changing from one to the next printing line. The advance of the transfer paper may be either independent of or synchronized with the advance of the printing paper.

As an example, according to one form of carrying the invention into effect, the transfer paper supplied in the form of a continuous strip is drawn from a supply roll, passed underneath the printing sheet and past the printing point upon the platen roller and thereafter rewound upon a takeup roll. In order to effect an automatic advance, the feeding mechanism for the transfer paper is mechanically coupled with the line advance mechanism for the printing paper, in such a manner as to eflfect a simultaneous step by step advance of the transfer paper together with a printing paper when changing from one to the next printing line. However, while the printing paper is advanced according to a desired adjustable line spacing, advance of the transfer sheet is fixed, being equal to the height of the largest printing type.

Furthermore, according to a preferred embodiment, the transfer strip may be passed through a pair of friction rollers, one of which has attached thereto a ratchet cooperating with a pawl similar to the pawl and ratchet line advance mechanism of a conventional typewriter structure. In this case the advance mechanism for the transfer strip or paper may be operated in substantially the same manner as the line spacing mechanism, either manually or automatically by the provision of a suitable coupling connection, as will be described in greater detail hereinafter.

In order to enable an easy incorporation of a device of this type in a conventional typewriter structure, such as by simply replacing a standard platen roller by a special roller or attachment unit, it has been found desirable to pass the transfer paper or strip from its supply roll past the printing point on the platen roller first in one direction and then in a reverse direction to enable the feed or advance mechanism to be mounted upon the top side of the platen roller. This makes it possible to construct the device in the form of a simple and compact unit suitable as an attachment for the conventional typewriter structures. In such an arrangement, however, the transfer paper on its return path over the platen-roller has its pigment coated surface in contact with the platen surface. This has the disadvantage of the platen surface becoming soiled by the residual printing ink or pigment left upon the transfer paper.

In order to prevent soiling of the platen by the residual pigment, it has been found desirable to provide the surface of the platen roller with a protective cover to which the pigment is applied or transferred under the effect of the typing impressions. Although substantially all the pigment has been removed at the areas of the typing impressions, enough residual pigment is left on the transfer sheet to cause soiling of the platen surface. This in time causes an accumulation of pigment upon the platen surface and softening thereof to an extent as to prevent a sharp or crisp type impression upon the printing sheet. As a result it is necessary to frequently clean the platen or to renew its protective cover.

In order to eliminate this last drawback, there is provided in accordance with an improved feature of the invention a special protective strip or paper in contact with the transfer paper and serving to prevent soiling of the platen surface by transfer of pigment from the transfer paper, said protective paper also being arranged to move independently of the platen roller and past the printing point. In this manner, each area of the protective paper receives only a slight amount of pigment, thereby insuring a crisp and uniform type impression upon the printing paper under all conditions.

The protective paper is advanced advantageously together with the transfer paper by a distance equal to the height of the printing type at the instants of changing from one to the next printing line. The protective paper may be fed to the type printing point either in the direction of or opposite to the line advance movement of the platen roller. The latter arrangement is preferable in that the protective paper is fed in the same manner as the transfer paper, both papers being advantageously drawn from suitable supply rolls first in one direction past the printing point and around suitable reversing rollers and then past the printing point again in the opposite direction and through a common feed or advance mechanism, such as a pair of friction rollers or the like. In such a construction, the protective and transfer papers are passed over the friction rollers with the pigment coated side of the transfer paper in contact with the soiled surface of the protective paper. This arrangement has the further advantage of preventing soiling or smudging of the hands of the operator when removing the used transfer paper. The superposed protective and transfer papers emerging from the feeding mechanism may be simply removed by cutting or tearing from time to time.

A further advantage of the latter construction is the fact that the transfer paper may be provided in the form of a continuous roll providing a pigment area sufii cient for producing a large number of printing sheets without change of transfer paper.

Referring more particularly to Fig. l, the numeral 19 indicates the platen roller of a conventional typewriter, a printing sheet 11 of paper or the like pressed into contact with the platen surface by means of pres sure rollers 12 and 13 being arranged for step by step advance past the type printing point P, in a manner customary in the operation of conventional typewriters. A transfer paper or strip 14 is drawn from a supply roll 15 past the printing point P, first in a downward direction and then in the opposite direction, upon reversal by means of a reversing roller 16, and rewound upon a takeup spool 17. This transfer strip being interposed between the platen 10 and printing sheet 11, has its outer surface in contact with the sheet 11 coated with a uniform layer of pigment or printing ink to be transferred to the printing sheet at the areas of the type impressions. The printing sheet 11 is advanced step by step in the customary manner during the operation of the carriage return lever by distances corresponding to a selected line spacing. The transfer paper 14, on the other hand, is advanced independently of the printing sheet by means of suitable feeding or advance mechanism (not shown). The latter may be in the form of a pawl and ratchet mechanism operated manually or automatically by coupling with the line advance mechanism, in such a manner as to advance the transfer paper step by step by increments equal to the height of the largest printing type, i. e. independently of the adjusted line spacing distance for the printing sheet 11. Accordingly, substantially the entire pigment area of the transfer paper will be used after a single passage through the typewriter, whereby to result in an optimum economy or substantial elimination of wastage of transfer paper.

In arrangements of the type according to Fig. 1, the transfer sheet 14 during its return movement is in contact with the platen roller 10, thus causing soiling of the latter by the residual ink or pigment left between and after the typing impressions. As a result, enough pigment may accumulate upon the platen surface liable to interfere with the crispness and sharpness of the type impressions upon the printing sheet 11. In order to prevent this drawback there is provided, as shown in Fig. 2, a protective strip 18 of plain paper or the like arranged for independent passage between the transfer strip 14 and the platen 10 and serving to protect the latter from soiling by residual pigment transfer.

According to a preferred construction or embodiment, as shown in the drawing, both the transfer paper 14 and protective paper 18 are drawn from supply rolls 15 and 20, respectively, past the printing point P, first in one and then in the reverse direction, by passing over a pair of suitable reversing rollers 16 and 21. Both return portions of the strips are then superimposed and passed through a suitable advance or feeding mechanism, such as a pair of friction rollers 22 and 23, as shown in the drawing. More specifically, the transfer paper is passed in contact with the printing sheet 11 while the protective paper 18 is passed in contact with the platen iii, whereby both the pigment carrying sides will be on the inside of the superposed strips upon emerging from the rollers 22 and 23. The used portions may thus be cut or severed from time to time without the danger of soiling the hands of the operator and smudging of the printing sheets.

In order to advance the transfer and protective papers, either of the rollers 22 may be connected with a suitable step by step feeding mechanism advancing both strips by increments equal to the height of the printing type and operated either manually or automatically by the line advance mechanism of the platen 10.

An arrangement of this type is diagrammatically illustrated in Fig. 3. In the latter, the numeral 25 represents the usual line spacing ratchet associated with the platen roller 10 and cooperating with a pawl 26 pivoted at 27 to a bent lever 28, the latter having a fulcrum point shown at 30. Upon deflecting the end of the lever 28 as indicated by the arrow during the initial movement of the carriage return lever (not shown) of a conventional typewriter, pawl 26 engages the ratchet 25, thus rotating platen 10 by an increment corresponding to the desired line spacing distance. The position of pawl 26 is adjusted to control the line spacing by the number of incremental movements of the ratchet 25, in a manner well known with standard typewriter constructions. A similar ratchet 31 is associated with the friction feed roller 23 (see Fig. 2) and cooperates with a pawl 32 attached to a bent lever 33 having a fulcrum point 34 Both levers 28 and 33 are operated simultaneously by the provision of a suitable coupling connection, as indicated at 35, in such a manner as to cause the pawl 32 to advance the ratchet 31 and in turn the superposed transfer and protective strips 14 and 18 by increments equal to the height of the printing type simultaneously with the line spacing advance of the platen roller 10. As is understood, the position of pawl 32 is fixed and independent of the line spacing position of pawl 26.

The entire structure comprising the support and advance mechanism for the transfer and protective papers may be constructed as a single compact unit carried by or structurally combined with the platen 10, the latter being preferably removably mounted upon the carriage of a conventional typewriter structure for interchangeable use with the standard platen roller.

In the foregoing the invention has been described with reference to a specific illustrative device. It will be evident, however, that variations and modifications, as well as the substitution of equivalent elements for those shown for illustration, may be made in accordance with the broader scope and spirit of the invention as set forth in the appended claims. The specification and drawings are accordingly to be regarded in an illustrative rather than in a limiting sense.

What I claim is:

l. The combination with a typewriter having a carriage, a platen carried thereby and line-space mechanism to rotate said platen for step by step advancing a printing sheet past a fixed printing point adjacent to said platen, of means mounted upon said carriage to support a roll of pigment transfer strip having a width substantially equal to the width of said printing sheet, and means for separately advancing said strip between said sheet and platen and past said printing point in one direction and reversing and repassing said strip past said printing point in the opposite direction, whereby to cause the oppositely moving portions of said strip to engage one another at said printing point.

2. The combination with a typewriter having a carriage, a platen roller carried thereby and means for step by step line spacing advance of a printing sheet past a fixed type printing point, of means supporting a roll of transfer strip uniformly coated on one side with pigment material, a roll of protective strip, and means for separately passing both said strips past said printing point between said sheet and roller first in a direction opposite to the advance of said sheet and then in the reverse direction, the advance and return portions of said transfer strip being adjacent to said sheet with the pigment coated surface in contact with the underside of said sheet and the advance and return portions of said protective strip being adjacent to said roller, and operating means for step by step advancing the superposed return portions of said strips by increments substantially equal to the maximum height of the type impressions.

3. The combination with a typewriter having a carriage, a platen roller carried thereby and means for step by step line spacing advance of a printing sheet past a fixed type printing point, of means supporting a transfer strip uniformly coated on one side with pigment material, means for supporting a protective strip, means for separately passing both said strips past said printing point between said sheet and roller first in a direction opposite to the advance of said sheet and then in the reverse direction, the advance and return portions of said transfer strip being adjacent to said sheet with the pigment coated surface in contact with the underside of said sheet and the advance and return portions of said protective strip being adjacent to said roller, and means synchronized with said platen advance means for step by step advancing the super-, posed return portions of said strips by fixed increments substantially equal to the maximum height of the typing impressions.

4. The combination with a typewriter having a carriage,- a platen roller carried thereby and means for step by step line spacing advance of a printing sheet past a fixed type printing point, of means supporting a transfer strip uniformly coated on one side with pigment material, means for supporting a protective strip, means for separately passing both said strips past said printing point between said sheet and roller first in a direction opposite to the advance of said sheet and then in the reverse direction, the advance and return portions of said transfer strip being adjacent to said sheet with the pigment coated surface in contact with the underside of said sheet and the advance and return portions of said protective strip being adjacent to said roller, a pair of friction drive rollers engaging the superposed return portions of said strips, and means for step by step rotating one of said rollers to advance the superposed strips by increments corresponding to the maximum height of the type impressions.

5. The combination with a typewriter having a carriage, a platen roller carried thereby and means for step by step line spacing advance of a printing sheet past a fixed type printing point, of means supporting a transfer strip uniformly coated on one side with pigment material, means for supporting a protective strip, means for separately passing both said strips past said printing point between said sheet and roller first in a direction opposite to the advance of said sheet and then in the reverse direction, the advance and return portions of said transfer strip being adjacent to said sheet with the pigment coated surface in contact with the underside of said sheet and the advance and return portions of said protective strip being adjacent to said roller, a pair of friction drive rollers engaging the superposed return portions of said strips, and means synchronized with said platen advance means for step by step rotating one of said friction rollers to advance the superposed strips by increments corresponding to the maximum height of the type impressions.

6. The combination with a typewriter having a carriage, a platen carried thereby and line-space mechanism including line-spacing adjusting means to rotate said platen for step by step advancing a printing sheet past a fixed printing point adjacent to said platen, of means mounted upon said carriage to support a pigment transfer strip having a width substantially equal to the width of said printing sheet, and means controlled by said linespace mechanism for passing said strip by fixed increments between said sheet and platen and past said printing point in one direction and reversing and repassing said strip past said printing point in the opposite direction substantially independently of the line spacing adjustment, whereby to cause the oppositely moving portions of said strip to engage one another at said printing point.

7. The combination with a typewriter having a carriage, a platen carried thereby and line-space mechanism including line spacing adjusting means to rotate said platen for step by step advancing a printing sheet past a fixed printing point adjacent to said platen, of means mounted upon said carriage to support a roll of pigment transfer strip having a width substantially equal to the width of said printing sheet, and means controlled by said line-space mechanism for passing said strip between said sheet and platen by fixed increments equal to the maximum height of the type impressions and past said printing point in one direction and reversing and repassing said strip past said printing pointin the opposite direction substantially independently of the line spacing adjustment, whereby to cause the oppositely moving portions of said strip to engage one another at said printing point.

8. The combination with a typewriterhaving a carriage, a platen carried thereby and line-space mechanism for rotating said platen to step by step advance a printing sheet past a fixed printing point, of means mounted upon said carriage to support a roll of pigment transfer strip and a roll of protective strip, both said strips having a Width substantially equal to the Width of said printing sheet, means for separately passing both said strips past said printing point between said sheet and platen first in one direction and then in the opposite direction, the advance and return portions of said transfer strip being adjacent to said sheet and the advance and return portions of said protective strip being adjacent to said platen, means for superimposing the return portions of both said strips, and means controlled by said line-space References Cited in the file of this patent UNITED STATES PATENTS 2,085,993 Nelson July 6, 1937 2,216,409 Etheridge Oct. 1, 1940 2,244,095 Botham et al. June 3, 1941 FOREIGN PATENTS 381,360 Germany Sept. 19, 1923 

